Dental instrument



Oct. 7, 1947. A. E. SYKES DENTAL INSTRUMENT Filed Feb. 23, 1946 INVENTOR. ALGEET E. 5YKE5" Patented Oct. 7, 1 947 UNITED STATES o-FFice 2,428,689 nEN'rAL-INsTRUMaN'i Albert E. Sykes, BerkelemGalif-z Application February 23, 194s:swans-mart 8 Claims.

This invention relates to instruments employed in the processes of tooth' reconstruction.

An object of the invention isto provide a hand tool particularly adapted to the removal from teeth of temporary cap members employed in taking impressions for permanentjacke'ts, inlays or crowns for the teeth.

A further object of. the invention is to-provide; inan instrument of the character described, ei-' fectively operatingtong members for-'tenaciously gripping a'cap member andfo'rmaintaining said grip while the cap member isbeinglifted from a tooth.

Another object of th invention'is to-provide a simple lever device, for lifting impression caps from teeth, in which a degree of pivotal movement is permitted in the planeof movement of the lever so as to produce a substantially linear lift on the caps regardless'of the fact that the immediately adjacent portion of the lever is moving in an ar-cuatepath. v

Still another object of the invention is to provide an instrument of thecharacter described which is comparatively compact andwhich will provide a satisfactory degreeof' operational visibility when it is in" use in a patients mouth.

Yet another object of the invention is to provide; in'an'in'strum'erit of the character described having opposed to'ngmenib'ers relatively movable between positions to grip and to engage a cap member, means under control of theo'perator for" releasably holding saidtong m'e'mbe'rs'dn one of said positions.

The invention possesses 'otherobj'ect's and features of adv'arltage',"som'eof which, with'the fore going, will beset forthin" the following description of the preferredform" of the invention which is illustrated'in'the drawing accompanying and forming part of the specification; It'is to be understood, however; that variations in the showing made-by the said drawingand specificationma'y be adopted within the-scope of the" invention as set-forthin the claims;

Referring 'to the drawing Figure 1' is a top-plan'view' of theinstrument-'- of my invention.

Figure 2 is a side elevational view of themstrurnent of invention" showingits I application in the removal of a: cap from'a tooth. V

Figure 3 is anenlarged vertical sectional View taken inthe plane indicated-by the 1ine--'3-3 of Figure 2.-

Figure e-is a vertical sectio'nalview taken in the plane'indicatedby the'linei -ll of Figure 3. The parts are-shown in their respective positerial such as wax, gutta percha orothe'r demarimpressi'o'n compound around andto enclose the tooth, extreme care" must beexercised in remov' ing" the wait: witlr it's" imprint from the tooth so exact size and form: of the 'toothf Anys'lightdevlaltibnflom'a lineal as it'o accurately retain the movementperpendicular to the tooth may resultinan impression which is" distorted" or enlarged" and'the cap; jacketf or inlay subsequently made in par-t 'f'rom "the' impre's'sionwill not fit properly when applied tothe .t'oo'th with' the result that" recalling-of the patient and the' tallfi'ngof a'siib-" sequentgimpres's'ion is often necessary. It is com mon' practice among many "dentists'to remove the wad of impression niaterial witlithe aid'of for ceps.

lapsinjgof the cavity; 1

. I have-provided an'irrstriiment', designed for facilitating impression-taking* of the character described; which if properly'arid" carefully used;- will-insurea 'maximum -proport'ion of acceptable impressions. As-will be se'eri in Figure 3; the t'ooth 6, in this case to b'e' fittedwith a'crown or jacket} -is enclosedby a tubular cap-"of shell 1 containing= one of'- thenpreviously mentioned impres sion compofinds": 8 which" e'ntirelysurrounds the 1 tooth: Notchs "9' areprbvided atdiametrically-'1 opposed positions on' "the shell 'l me are remiss: by depressing on displacing inwardly" side" wall portions of the "shell; The' instrumentpwhich is engageab-le 'with and" to lift the" shell from the tooth, is cbmposed of the' usual hexagon rod" of 1 which "most dental instruments of this general type are constructed; and comprises a handle portion Ilturned down at' oneend'to form a shank" l 2 having a'fiang'e l arr om which extends in axial alignmentwith th'e handle' and' shank,

'a stem-l4 having 'a threadedend portiom 16, on

take an indented impression ofihis procedureiahowever, very likely to produce alargei proportion of faultyimpressions? since the lateral pressure of the forceps jaws" on the material, as tlie'wa'dis separated from the" tooth; may" be sufficient to cause a decided c'o'l' 3 which is engaged a nut I1, and an integral axially extending portion bent, preferably rectangularly with respect to the common axis of the handle, shank and stem, to form a stud I8. I provide a pair of cooperative grip members on the lever portion of the instrument above described, each of which comprises a wing I9 provided with an aperture 2| for receiving the stem |4 so that the wing is journaled on and extends radially from the stem. The aperture 2| of each wing is substantially larger in diameter than the stem so that the grip members are free to tilt, to a certain degree, on and in a direction axially of the stem. The respective wings l9,

which extend in opposite directions radially of the stem as shown in Figure 2, are each provided with an integral downwardly extending arcuate claw 22 having at its distal end a slightly up turned hook 23 adapted to engage in the transverse plane shoulder of the shell notch 9. Tabs 24-, also formed integrally with the wings l9, extend upwardly from the latter in relatively spaced relation and form control elements which, upon being squeezed together will cause the claws 22 to spread apart andrelease the shell ,7. An arcuate notch 26 formed in one of the wings l9, and concentrically with its ates with a pin 2! fixed in the other limit the degree of relative recession proach of the claw hooks 23, and a spring having opposed, radially extending end portions28 secured in apertures 29 provided in each grip member, serves to normally urge the claws 22 toward each other.

Means is provided, undercontrol of the operators handholding or manipulating the instrument, for operating the claws to efiect opening or closing thereof. Mounted on and for Wing to slidable movement longitudinally of the handleportion H is a sleeve 3| provided with forwardly and rearwardly extending fingers 32 and 33 respectively, the former of which has an integral head portion 34 provided with an aperture 36 having angularly related sides 31 converging toward the sleeve 3| and lying adjacent the outer sides of the tabs 24. The rearward extending finger 33 has a loop'38 therein at its junction with the sleeve which performs the dual function of a finger grip and of a spring urging the finger 33 against the side of the handle portion The outer end of the finger 33 is provided with a protuberant portion 39 which, as the sleeve 3| is moved along the handl portion may snap into a notch 4| formed in the'side thereof so as to hold the sleeve fixedly related to the handle portion until the sleeve is manually released. The shape of the aperture 38, it will be noted, is such that when the tabs 24 are positioned at the wider part thereof, as shown in Figure 1, the claws 22 will be free to approach each other to engage the impression shell 1. However, by pushing the sleeve 3| along the handle portion I toward the shank l2, the head 34 will be correspondingly moved to force the tabs toward the narrower end of the aperture 36. This will bring the tabs together and similarly spread the claws 22 so as to release their engagement with the impression shell. Simultaneously, the protuberance 39 will engage the notch 4| so that the claws will be held in relatively extended positions until counter-movement of the sleeve on the instrument handle portion releases them. This mechanical operation of the claws is particularly valuable when work is being done toward the rear of the mouth since it permits aperture 2|, cooperand apone-hand manipulation of the instrument thus insuring a maximum of visibility for the operator and a minimum obstruction to illumination of the work area.

The method of application of the instrument is illustrated in Figure 1. Here it will be noted that the instrument is positioned above and substantially paralleling the row of teeth with the claws engaging the shell I, which has been previ ously arranged on the tooth under treatment, and with the stud i 8 resting on top of the immediately adjacent tooth. The handle portion ll of the instrument is now lifted vertically, toward the dotted line position thereof indicated in Figure 1, so as to elevate the shell relative to the tooth as indicated in Figure 3. It will be further seen in Figure 3 that the oversize apertures 2| in the grip members permit the latter to retain, and to move in, a linear path, which coincides with the vertical longitudinal axis of the tooth, while the lever portion of the instrument is moving in an arcuate path, This insures that the medial or distal portionsof the impression shell will not be moved laterally of the tooth during removal of the former which might cause possible distortion of the toothimpression and the production of a faulty andill-fitting cap, jacket or inlay. It will be noted, in addition, that the portions of the claws 22 immediately adjacent the hooks 23 are bent in offset relationship with the main bodies of the grip members so that the hooks lie in the same plane transaxially of the shell. This insures that symmetricallifting forces are applied to the opposite sides of the shell and further lessens the chances of impression distortion due to twistingor rocking of the shell relative to the tooth.

The instrument illustrated in Figures 1 to 3 inclusive is capable of operations on all teeth,

with the exception of the rearmost molars, which ment which will operate on any tooth including the rearmost molars which has an adjoining tooth forwardly of the mouth. This I accomplish by' providing the shank I? with a radially extending stud 35 which is comparable to the stud 8 but which is located on the handle side of the grip members. The shank i2 is also provided with an upwardly extending angularly bent portion 35 which serves to position the handle H in a desirably upwardly inclined position. This upward inclination of'the handle extends the range of downward swing of the latter and consequently increases the range of life of the impression shell.

The positioning of the fulcrum stud forwardly of the grip members serves, of course, to permit this instrument to operate on any tooth in the mouth, rovided of course that the patient has a full set of teeth, or on teeth whose position would render the instrument of Figure 2 inoperative.

I claim: 1. In combination with an impression sleeve provided with spaced indentations and adapted to enclose a tooth under treatment, a lever having opposed gripping elements thereon for engaging the indentations of said sleeve, and said lever having a portion thereof extended to engage an adjacent tooth to provide a fulcrum about which said lever may be moved to lift said impression sleeve from the tooth under treatment.

2, In combination with an impression sleeve provided with spaced indentations and adapted to enclose a tooth under treatment, a lever having opposed gripping elements thereon for engaging the indentations of said sleeve, said lever having a portion thereof extended to engage an adjacent tooth to provide a fulcrum about which said lever may be moved in an arcuate path to lift said impression sleeve from the tooth under treatment, and said gripping elements during movement of said lever being moved along a linear path substantially coinciding with the vertical longitudinal axis of said tooth under treatment.

3. In combination with an impression sleeve provided with spaced indentations and adapted to enclose a tooth under treatment, a lever having opposed gripping element thereon for engaging the indentations of said sleeve, said lever adjacent an end thereof havin an integral portion thereof extended to provide a fulcrum engaging an adjacent tooth and about which said lever may be moved to lift said impression sleeve from the tooth under treatment, said gripping elements being mounted on said lever for rocking movement transversely and longitudinally thereof, and means for urging said gripping elements together to engage said impression sleeve.

4. In combination with an impression sleeve provided with spaced indentations and adapted to enclose a tooth under treatment, a lever having at one end thereof a shank provided with an extended stud for engaging an adjacent tooth to constitute a fulcrum about which said lever may be moved, a pair of gripping elements pivoted on said shank and having opposed claws for engaging the indentations of said sleeve, and means interposed between and for urging said gripping elements together to maintain engagement of said claws in said indentations.

5. In combination with an impression sleeveprovided with spaced indentations and adapted to enclose a tooth under treatment, a lever having at one end thereof a shank provided with an extended stud for engaging an adjacent tooth to constitute a fulcrum about which said lever may be moved, a pair of gripping elements pivoted on said shank to move transaxially thereof and having opposed claws for engaging the indentations of said sleeve, means on a gripping element cooperative with another gripping element to limit the degree of relative transaxial movement therebe-tween, said gripping elements being free for pivotal movement relative to and longitudinally of said shank, and means interposed between said gripping elements for urging the claws thereof to maintain their engagement with said indentations of the impression sleeve.

6. In combination with an impression sleeve provided with spaced indentations and adapted to enclose a tooth under treatment, a lever having at one end thereof a shank provided with an angularly extending stud for engaging an adjacent tooth to constitute a fulcrum about which said lever may be moved, a pair of wings journaled on and extending oppositely from said shank, said wings having therein enlarged apertures through which said shank passes and providing for a degree of rocking movement of said wings longitudinally of saidshank, claws on said wings provided at their distal ends with hooks for engaging the indentations of said impression sleeve, one of said wings having therein an arouate notch within which operates a pin carried by the other wing and cooperative with said pin to limit relative pivotal movement of the wings about the axis of said shank, relatively spaced tabs extending from said wings and manually engageable to move said claw hooks apart to release said impression sleeve, and a spring interposed between wings for urging said claw hooks together,

7. In combination with an impression sleeve provided with spaced indentations and adapted to enclose a tooth under treatment, a lever having at one end thereof a shank provided with an angularly extending stud for engaging an adjacent tooth to constitute a fulcrum about which said lever may be moved, a pair of wings journaled on and extending oppositely from said shank, said wings having therein enlarged apertures through which said shank passes and providing for a degree of rocking movement of said wings longitudinally of said shank, claws on said wings provided at their distal ends with hooks for engaging the indentations of said impression sleeve, tabs on and rising from said wings in spaced relative relationship, a spring interposed between said wings for urging said claw hooks together and said tabs apart, and an actuating member mounted for movement on said lever, said actuating member having a portion thereof engageable with said tabs to move said tabs toward each other and to move said claws apart.

8. In combination with an impression sleeve provided with spaced indentations and adapted to enclose a tooth under treatment, a lever having at one end thereof a shank provided with an angularly extending stud for engaging an adjacent tooth to constitute a fulcrum about which said lever may be moved, a pair of wings journaled on and extending oppositely from said shank, said wings having therein enlarged apertures through which said shank passes and providing for a degree of rocking movement of said wings longitudinally of said shank, claws on said wings provided at their distal ends with hooks for engaging the indentations of said impression sleeve, tabs on and rising from said wings in spaced relative relationship, a spring interposed between said wings for urging said claw hooks together and said tabs apart, an actuating member mounted for movement on said lever and having a portion thereof engaged with and to move said tabs toward each other upon movement of the actuating member relative to the lever, and means to releasably secure said actuating member, in one position of movement thereof, on said lever.

ALBERT E. SYKES. 

